27
Maintenance
Doc No: OMMB00301 Revision: 1 – Nov 2019
1. Refer to Figure 2. Remove housing nuts (Item 12) and split
valve. Remove the lower housing (Item 2) taking care not to
damage the elements. Remove and discard housing gasket
(Item 9) ensuring any traces of the gasket are removed from
the housing mating faces. Note that in some sizes of Model B
Valves ‘O’ rings are used instead of gaskets.
2. If removing element from BO valve (without manual override)
that is not 5”, 6” and 8” steel valve, simply pull the element
from the upper housing. Go to step 10.
3. If removing element from BO valve (without manual override)
that is 5”, 6” and 8” steel valve, simply pull the element from
the upper housing. Go to step 7.
4. If removing element from BR valve (manual override) only
dismantle one at a time to eliminate the chance of the manual
override parts being mixed up.
5. Carefully remove the indicator pin (item 36).
6. Remove the locknut (Item 38) from the override stem (Item
21).
7. Remove override housing retaining screws (item 28). For 5”, 6”
and 8” steel BO valve, remove cap plate (item 44 on Figure 3)
and go to step 10.
8. Unscrew override housing from the override stem (Item 21) and
set aside the shims.
9. Pull the element from the upper housing and if changing the
element unpin the override stem from the element link.
10. Remove ‘O’ rings. For BR valve, 5”, 6” and 8” steel BO valve,
item 7 & 17. For other BO valves, item 7.
11. Inspect valve seat for wear or damage. If required replace valve
seat (Item 3), remove by unscrewing bushing (Item 5). Bushing
A/F 7/8”.
7.2 Reassembling the valve
1. Where fitted, lubricate gasket (Item 9) liberally with a good grade
of petroleum grease, allow to soak.
2. If valve seat changed, refit bushing with Loctite 2400 locking
compound.
3. Lightly grease and stretch new ‘O’ ring (Item 7) and fit into upper
housing. Position ‘O’ ring concentrically to assist element
assembly.
4. If replacing a BR valve element, then fit override stem (Item 21)
to element link with pin (Item 20).
5. Insert element into the upper housing taking care not to damage
the ‘O’ ring.
6. For BO valves that is not 5”, 6” and 8” steel valve, go to step 11.
To Next Page
Loading...
